A dependency-free (pure standard-library) Python tool that turns the streaming QoE metrics this article frames into an estimated engagement impact, using the published causal/empirical models so the output traces to a citable source. It does NOT decode video or compute picture metrics; it consumes the session-level numbers a player analytics stack already reports. (1) STARTUP -> ABANDONMENT: applies the Krishnan-Sitaraman (IMC 2012) finding — abandonment begins past ~2s and rises ~5.8 percentage
Download free PDF

The handbook · 7 volumes
Fora Soft Video Engineering Handbook
This Python calculator turns startup time, rebuffering and bitrate into an estimated engagement impact using published models. Our seven-volume handbook covers the levers behind each number: Volume 3 on ABR, CDNs, players and QoE monitoring, Volume 1 on encoding quality per bit, and Volume 6 on AI models that predict viewer response. Written by Nikolay Sapunov, CEO at Fora Soft.
Need to show how much rebuffering and slow startup cost you in watch time?
Send us your player analytics: we return an engagement-impact estimate per QoE metric and the delivery fixes with the best return. 250+ video products shipped since 2005.